A series on the current work of Fellows of the Royal Society
by H. W. Lissman, F.B.S. and R. D. Keynes, F.R.S.
Some fish generate extraordinarily high electrical voltages to stun their prey; others find their way about by emitting extremely weak electrical impulses. How they do this has intrigued scientists for more than two hundred years.
Outside Broadcast cameras visit the Department of Zoology at Cambridge to investigate the research of two scientists who are near the final answer.